Need some help with high torque 408 build

I built a 422 for my 72 Duster. Stock Eddie heads Hughes hyd flat tappet cam 236*244*/550 ish lift/11.2:1 compression. Could not believe the torque. So much I had to swap from 4.30s to 3.23. At wide open throttle from 2100 rpm up there is significant vacuum 1 inch trending upwards to 4+ at 6000 RPM the 750 must be too small.
My point to that is, strokers demand allot of air that a stock head will struggle to support. Quench is also difficult to build for two seperate heads unless both heads are closed chamber and similar CCs.

I am now in the process of building a 408 like you are describing. High torque yet 6000 to 6500 rpm is needed.
I had Hughes choose my cam for this build 228*236*/544. lift hyd roller the heads are the 2.02 valved RHS X heads by Brian at IMM who seemed to approve of the cam selection for this build. Compression will be 9.7:1 with. 039 quench.
Having said all this i would've liked a recipe book to choose builds from. I think anyone wanting to can screw one together but a well planned build will net better results. I am learning this now the hard ways time and money.